What is a wiki?
A wiki is a fast way to create a page. You can within a minute create a new page from scratch. There is no HTML needed, you can edit clear text like in any text editor and most common things are very easy to learn. It is meant to be edited by everyone and anyone. You can add more information and edit existing info.
Who can edit here?
Everyone who registers here can edit the pages. Registrations only requires user name and password (email optional) and is done within 20 seconds. You see a typo, go and fix it. You have to add something, a better way, a shortcut or something else you see missing, go ahead and add it.
I can't program or write HTML what about me?
It is very easy. There are only two special things you need to know. One is that you can make links inside the wiki by using the [ brackets. Like [[this]]. It would create a link to a page called "this" on that same word. The second is titles. You can make them by simply adding two equal signs on each side of the text. More help needed? Just edit a page without changing anything and watch how it has been done in there, and copy it. You can also ask questions, or look through the manuals.